I searched everywhere for the answer to the same question and all of the answers involved patching (whatever that is) and other ways that I, not knowing too much about technology, found hard to understand. Untill I came across this site....http://www.linfoxdomain.com/nintendo/ds
go there and on the column on the right look for R4 DS, click on that and select which language you want, for me it was R4_v1.18_English.zip 5.11 MB, I downloaded this and took all of the files that came with it, and replaced the files with the same name on my R4 card, with these. Now all of the games I downloaded that once said "save data could not be accessed", all work perfectly fine. Hope this was easy enough to understand and helped....lol
Luke G, June 2009
